**12. Aspects of angiography and angioplasty**


Mann-Whitney U test

**Infarct in T2**

1 Patient

3 NF/patient 4 Standard deviation Mann-Whitney U test

first MRI

Logistic regression analysis

**NF**

**n pt1 %2 n pt %**

With 8 44.4 15 83.3 0.037

**Table 16.** Distribution of NF according to the presence of previous cerebral infarct (in T2) in the first MRI

**Infarct in T2 n of NF %1 n of pt2 Average3 SD4 p** Without 3 5.08 13 0.23 0.44

With 56 94.92 23 2.43 3.31 0.011

**Table 17.** Distribution of the number of NF (after CAS) based on the presence of previous cerebral infarcts in T2 in the

**Figure 7.** Patient number 19, 81 years old with bilateral stenosis in the carotid arteries. A DSA was performed in the aortic arch, common carotid arteries, left subclavian artery, and brachiocephalic trunk before the CAS of the left caro‐ tid artery. Diffusion study before the DSA and angioplasty (A). After DSA and CAS, an NF was identified in the DWI in the left hemisphere of the cerebellum (B). A new MRI performed 40 days after the CAS (not as part of the study proto‐

Without 10 55.6 3 16.7

TOTAL 18 100.0 18 100.0

2 Percentage of patients in the group with NF (n=18)

170 Carotid Artery Disease - From Bench to Bedside and Beyond

TOTAL 59 100.0

1 Percentage related to the complete NF group (n=59)

2 Number of patients with cerebral infarct images on the initial MRI

col) showed the absence of lesions in the DWI (C) and in T2 (not shown).

**No Yes p**

**Table 18.** Average degree of stenosis in the groups with and without NF after CAS


Logistic regression analysis

**Table 19.** Presence of ulcers and appearance of NF after CAS


**Table 20.** Distribution of NF according to the presence of contralateral carotid occlusion.


**Arteries submitted to angiography**

Logistic regression analysis

**Type of exam (n=36)**

pt: patients

**carotid**

Logistic regression analysis

**Technique used to access**

2 Percentage of access technique Logistic regression analysis

**NF**

**n % n %** RCCA 13 72.22 16 88.89 0.220 RSUB1 4 22.22 2 11.11 0.379 BAT 6 33.33 9 50.00 0.313 ARCH 4 22.22 5 27.78 0.701 LSUB2 8 44.44 10 55.56 0.506 LCCA 15 83.33 14 77.78 0.675

RCCA: right common carotid artery; LCCA: left common carotid artery; ARCH: aortic arch; RSUB: right subclavian artery;

**NF**

**Catheterization techniques**

**n1 %2 n1 %2**

DA 6 50.00 6 50.00 1.000 ECC 5 50.00 5 50.00 1.000 EEC 4 36.37 7 63.64 0.283 TRI 6 75.00 2 25.00 0.124 DA: direct access; ECC: exchange in the common carotid artery; EEC: exchange in the external carotid artery; TRI: triaxial

**Without NF With NF p**

**n of pt % of exams n of pt % of exams**

"Broad" (n=24) 11 45.83 13 54.17 0.480

**No Yes p**

**Table 25.** Number and percentage of each vessel subjected to DSA and the appearance of NF after CAS

"Brief" (n=12) 7 58.33 5 41.67

**Table 26.** Type of angiographic exam used and the appearance of NF after CAS

1 Number of times that each technique is used in the group with and without NF

**Table 27.** Correlation of catheterization techniques with NF after CAS

LSUB: left subclavian artery; BAT: brachiocephalic arterial trunk 1 RSUB includes angiography of the ipsilateral vertebral artery 2 LSUB includes angiography of the ipsilateral vertebral artery

**No (n=18) Yes (n=18) p**

http://dx.doi.org/10.5772/57154

173

Cerebral Protection in Carotid Angioplasty – Is There a Need? Advantages and Disadvantages of...

min: minute

Mann-Whitney U test

**Table 21.** Correlation of fluoroscopy time with NF after CAS


Mann-Whitney U test

**Table 22.** Correlation of contrast volume used in the CAS and the appearance of NF after CAS


1 Total number of catheters used in each group

2 Average catheter/patient

Mann-Whitney U test

**Table 23.** Number and average of catheters used in the CAS according to the presence of NF in the final MRI


Mann-Whitney U test

**Table 24.** Number and average of vessels subjected to DSA according to the presence of NF after CAS


RCCA: right common carotid artery; LCCA: left common carotid artery; ARCH: aortic arch; RSUB: right subclavian artery; LSUB: left subclavian artery; BAT: brachiocephalic arterial trunk

1 RSUB includes angiography of the ipsilateral vertebral artery

2 LSUB includes angiography of the ipsilateral vertebral artery

Logistic regression analysis

**NF Total time (min) Average**

172 Carotid Artery Disease - From Bench to Bedside and Beyond

**Table 21.** Correlation of fluoroscopy time with NF after CAS

**Volume (ml)**

Without NF 43 2.39

1 Total number of catheters used in each group

1 Vessels subjected to angiography per patient

min: minute

**NF**

ml: milliliter

Mann-Whitney U test

2 Average catheter/patient Mann-Whitney U test

Mann-Whitney U test

Mann-Whitney U test

Without (n=14) 323 23.07 10.48

Without (n=16) 2910 181.88 73.50

**(min)**

With (n=15) 342 22.80 8.59 0.880

**Average (ml)**

With (n=14) 2570 183.57 54.01 0.918

**Table 22.** Correlation of contrast volume used in the CAS and the appearance of NF after CAS

**Patients n of catheters1 Average2 p**

With NF 40 2.22 0.462

**Patients n of vessels undergoing DSA Average1 p**

Without NF 50 2.78 0.628

**Table 24.** Number and average of vessels subjected to DSA according to the presence of NF after CAS

With NF 56 3.11

**Table 23.** Number and average of catheters used in the CAS according to the presence of NF in the final MRI

**SD**

**SD**

**(min) <sup>p</sup>**

**(ml) <sup>p</sup>**

**Table 25.** Number and percentage of each vessel subjected to DSA and the appearance of NF after CAS


pt: patients

Logistic regression analysis

**Table 26.** Type of angiographic exam used and the appearance of NF after CAS


DA: direct access; ECC: exchange in the common carotid artery; EEC: exchange in the external carotid artery; TRI: triaxial

1 Number of times that each technique is used in the group with and without NF

2 Percentage of access technique

Logistic regression analysis

**Table 27.** Correlation of catheterization techniques with NF after CAS


**Filter brand**

Chi-squared test

2 NF ipsilateral 3 NFIP/filter brand Kruskal-Wallis test

2 NF ipsilateral

Mann-Whitney U test

of the filter during the CAS.

**Table 31.** Occurrence of NF based on filter brand (n=36)

1 Two patients were excluded from the analysis of laterality.

1 Two patients were excluded from the analysis of laterality.

NOTE: Eccentric, EPI®; Concentric, Angioguard® and Emboshield®

3 NF IP/filter system protection design

**NF**

Cerebral Protection in Carotid Angioplasty – Is There a Need? Advantages and Disadvantages of...

**No Yes**

**n % n %**

In this series, there was not a case in which excess thrombus or atheroma plaque materials determined acute occlusion

Emboshield® 2 28.57 5 71.43 0.367

Angioguard® 2 50.00 2 50.00

EPI® 14 56.00 11 44.00

NOTE: 100 µm pores in AngioGuard®, 110 µm in EPI FilterWire EZ®, and 140 µm in EmboShield®

**Filter brand n of uses NF IP2 Average3 p**

EPI® 24 23 0.958 0.582

**Table 32.** Distribution of NF ipsilateral to the use of the filter, considering the different models (n=34 filters1)

**Filter design n of uses NF IP2 Average3 p**

Concentric 10 21 2.100 0.515

Angioguard® 4 9 2.250 Emboshield® 6 12 2.000

NOTE: 100 µm pores in AngioGuard®, 110 µm in EPI FilterWire EZ®, and 140 µm in EmboShield®

Eccentric 24 23 0.958

**Table 33.** Distribution of NF ipsilateral to the use of the filters, considering filter design (n=34 filters1)

**p**

175

http://dx.doi.org/10.5772/57154

1 Stent/brand

Chi-squared

**Table 28.** Correlation of types of stent with NF after CAS


IP: ipsilateral

1 NF IP/stent

NOTE: In this data analysis, CASs with NF outside the area where the stent was implanted were excluded. Kruskal-Wallis test

**Table 29.** Correlation of stent brands with NF after CAS considering only the side where the stent was implanted


IP: ipsilateral

In this aggregation of the elements, CASs with NF outside the area where the stent was implanted were excluded

1 Two patients were excluded from the analysis of laterality.

2 NF IP/stent

Mann-Whitney U test

NOTE: Open-cell stent: Wallstent®; closed-cell stents: Precise® and Protégé®

**Table 30.** Correlation of stent designs with NF after CAS considering only the side where the stent was implanted (n=34 patients1)


Chi-squared test

**Brand of stent**

1 Stent/brand Chi-squared

IP: ipsilateral 1 NF IP/stent

IP: ipsilateral

2 NF IP/stent Mann-Whitney U test

(n=34 patients1)

Kruskal-Wallis test

**NF**

**n %1 n %1**

Wallstent® 12 54.55 10 45.45 0.493

**Stent brand n of stents with NF IP NF IP Average1 p**

NOTE: In this data analysis, CASs with NF outside the area where the stent was implanted were excluded.

**Table 29.** Correlation of stent brands with NF after CAS considering only the side where the stent was implanted

**Stent design n of stent with NF IP NF IP Average2 p**

Open cell 14 23 1.77 0.128

In this aggregation of the elements, CASs with NF outside the area where the stent was implanted were excluded

**Table 30.** Correlation of stent designs with NF after CAS considering only the side where the stent was implanted

Closed cell 20 21 1.05

Protégé® 5 5 1.00 0.245

Precise® 9 18 2.00

Wallstent® 20 21 1.05

Precise® 4 44.45 5 55.56 Protégé® 2 40.00 3 60.00

**Table 28.** Correlation of types of stent with NF after CAS

174 Carotid Artery Disease - From Bench to Bedside and Beyond

1 Two patients were excluded from the analysis of laterality.

NOTE: Open-cell stent: Wallstent®; closed-cell stents: Precise® and Protégé®

**No Yes p**

NOTE: 100 µm pores in AngioGuard®, 110 µm in EPI FilterWire EZ®, and 140 µm in EmboShield®

In this series, there was not a case in which excess thrombus or atheroma plaque materials determined acute occlusion of the filter during the CAS.

**Table 31.** Occurrence of NF based on filter brand (n=36)


1 Two patients were excluded from the analysis of laterality.

2 NF ipsilateral

3 NFIP/filter brand

Kruskal-Wallis test

NOTE: 100 µm pores in AngioGuard®, 110 µm in EPI FilterWire EZ®, and 140 µm in EmboShield®

**Table 32.** Distribution of NF ipsilateral to the use of the filter, considering the different models (n=34 filters1)


1 Two patients were excluded from the analysis of laterality.

2 NF ipsilateral

3 NF IP/filter system protection design

NOTE: Eccentric, EPI®; Concentric, Angioguard® and Emboshield®

Mann-Whitney U test

**Table 33.** Distribution of NF ipsilateral to the use of the filters, considering filter design (n=34 filters1)

In summary, our DWI MRI study after CAS found that 50.00% of patients showed NF of restriction/ischemia in DWI after CAS. All of the NF were clinically silent (100%). These NF were located in a cerebral area fed by the cerebral artery subjected to CAS in 77.19% of patients and an area smaller than 10 mm in 91.53% of patients. The NF in cerebral areas not fed by the cerebral artery undergoing angioplasty corresponded to 22.81% of NFs. The presence of previous cerebral infarcts on the MRI influenced the appearance of NF (p=0.037).

The institution wherein the present study was conducted published data pertaining to 1,037 carotid angioplasties with stent implantation and cerebral protection in 2006. The incidence of disabling neurological complications and death was 2.2% [38]. Despite the low morbi-mortality of the method, the real incidence of embolism is not known because the patients remained

Cerebral Protection in Carotid Angioplasty – Is There a Need? Advantages and Disadvantages of...

http://dx.doi.org/10.5772/57154

177

We found restriction foci in the diffusion MRIs of 18 of the 36 (50%) patients in our series. These NF in the DWI after CAS are additional to those in the first MRI, which implies that the procedure or some aspect of it is related to the appearance of NF. The fact that all of the patients in this series were asymptomatic after CAS and remained so during the intrahospital obser‐

The percentage of patients with NF in DWI in similar studies is quite variable: 9 to 78% (9% [74]; 15.8% [71]; 17.3% [48]; 20.4% [75]; 29% [56]; 30% [36]; 40% [61]; 41.5% [73]; 42% [46]; 42.6%

The comparison of different studies is very difficult because even a small variation in the period after the CAS during which DWI was conducted might affect the result. In the study by Rapp et al. [77], a total of 23 patients underwent two MRI exams after the CAS. The first MRI scan was performed immediately after the procedure (1 to 2 h) and the second exam was performed 48 h later. The results indicated only two (9%) cases with NF in the DWI immediately after the procedure and 18 (78%) cases with NF 48 h later [77]. In a recent meta-analysis that included studies that followed the evolution of CAS by DWI (1,363 CAS), NF were found in 37% of

The study that is most similar to ours is Kastrup et al. (2006); this study found microembolia in 49% of patients with cerebral protection. Two years later, the authors updated their series and published that NF occurred after CAS with a cerebral protection filter in 52% of patients

du Mesnil de Rochemont et al. [46] found NF in 42% of CAS and, similar to our study, found no neurological deficit. In addition to this study, several others [35,37,48,61,69,73] have found that most patients remained asymptomatic after CAS, despite the presence of NF. These

Jaeger et al. [56] demonstrated that smaller NF are less likely to become definitive lesions. His study showed that of the 59 restriction foci in the diffusion after CAS, only 17 (29%) were observed in the T2 sequence. They found that 17% of the lesions smaller than 5 mm in the DWI were visible in T2; 36% of the lesions in DWI between 5 and 10 mm were observed in T2, and 100% of the larger lesions (larger than 10 mm) were apparent in T2 [56]. As in Tedesco et al. [70], we considered the hypersignal images in T2 as already defined and permanent ischemia

In a series of 59 CASs, Jaeger et al. [56] found that 75% of NF were smaller than 5 mm; in the series by Piñero [48], the lesions were smaller than 5 mm in 57% of patients. However, in a series of 22 CASs in Roh et al. [78], all of the NF were smaller than 10 mm. In our study, small NF (<10 mm) corresponded to a large majority (91.53%) of the NF, while large NF (>10 mm)

findings encouraged us to look for factors that lead to ischemic changes.

foci, unlike the lesions in DWI, which may be reversible.

[69]; 43% [59]; 49% [34]; 52% [35], 54% [58], 59.2% [76]; 9 and 78% [77]; 70% [70]).

asymptomatic.

patients [37].

[35].

vation period should also be taken into account.
